Jury selection began Monday in the New York murder trial of a six-year-old boy who disappeared 35 years ago in one of America's most famous missing child cases.

Etan Patz vanished after leaving his parents' Manhattan townhouse to walk alone for the first time to the bus stop to go to school on May 25, 1979.

His parents only realized he was missing when he failed to return home at the end of the day. His body has never been found.

Missing: Etan Patz vanished after leaving his parents' Manhattan townhouse to walk alone for the first time to the bus stop to go to school on May 25, 1979

Chilling memory: People walk past a street shrine to six-year-old Etan Patz, in front of the building where suspect Pedro Hernandez confessed to having strangled the boy

The case became a national cause celebre and awakened millions of Americans to the dangers of child abduction, fueling a generation of vigilant child rearing by parents frightened to let their offspring out of sight.

Pedro Hernandez, 53, who worked in a nearby grocery store at the time, is on trial for the murder and kidnapping of Etan.

He confessed to police in 2012 to killing the boy, but has since recanted his confession and pleads not guilty.

He sat quietly in the New York state supreme court in Manhattan on Monday, dressed smartly in grey trousers, and a pin-stripped shirt and tie.